Dryim and roasting apparatus



(No Model.) 3 Sheets-Sheet 1.

H. PRASCH.v DRYING AND ROASTING APPARATUS. No. 418,315. Patented Deo. 3l, 1889.

N PETERS. PhnwLimogmphur. wnshingmn. D. C.

N0 Model.) Y 3 sheets-sheer. 2. H. PRASCH. DRYING AND ROASTING APPARATUS. No. 418,315. Patented Deo. 31, 1889.

l@ MLM .0127. MMM/2@ ANO Model.) 3 sheets-sheen 3.

H. FRASCH. BRYAN@ AND ROASTING APPARATUS.

110.418,315. Patented Dec. 31, 1889.

NA PKTERS. Pholvlhhogvzpher, Washington, DA C.

- UNITED STATES PATENT OFFICE.

HERMAN FRASOH, OF LONDON, ONTARIO, CANADA.

DRYING AND ROASTING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 418,315, dated December 31, 1889. Application filed May l0, 1886i Serial No. 201,762. (No model.)

- don, in the Province of Ontario, Canada, have vside of the roasting chamber.

invented certain new and useful Improvements in Drying and Roasting Apparatus, of which the following specification is a full, clear, and exact description.

This invention relates more particularly to an apparatus for drying the bicarbonate of sodium precipitated in the ammonia-soda manufacture and separated by filtration from the ammonium-chloride solution and for roasting it to complete its decomposition into monocarbonate of sodium; but it is applicable, at least in part, to the treatment of other substances. i

The invention consists in the parts, improvements, and combinations hereinafter particularly pointed out.

The following is a description of what is considered the best mode of applying the principle of the invention, reference being had to the accompanying drawings, which form part of this specification.

Figure I is a vertical section on dotted line II, Fig. VI, of a drier and roaster for bicarbonate ofsodium; Fig. II, a plan, one-half sectioned, of the drying or the roasting chamber; Figs. III, IV, and V, detail views of one of the shovels; and Fig. VI is a side elevation of the drier and roaster.

The feathered arrows indicate the tiow of escaping gas or vapor and the double-headed arrows the motion of the solid material.

The drying and roasting chambers A are substantially alike, as shown. They are set in brick-work, the drying above and at one Under the i'oastingcliainber, and also under the dryingchamber, near the circumference thereof, are the fire-places B. As many of these are used as necessary to heat the bottom of the chambers evenly. As shown, they contain each a grate 125, filled with loose stone 126. A gas-pipe 127 delivers the gas for fuel through numerous holes into the pit below the grate, and the air is supplied from a flue 12S through numerous holes in the wall of the ashpit. The flames play upon the stones and heat them to a high temperature. The

products of combustion from each nre-place or beams 134.

rings 132 and 133 and the connecting bars The inner ring 132 surrounds the stationary cylindrical tube 135 and runs upon rollers carried by brackets bolted to said tube. The outer ring 133 runs upon rollers carried by brackets bolted to the inner wall of the chamber. It is provided with 'cogs or teeth, which are engaged by the bevel-gears 136 on the two shafts 137. The latter are revolved by belts on pulleys 138 and serve to rotate the stirrer-fiame. By applying the driving-power to theframe at the periphery instead of to a shaft at the center the danger of twisting off shafts is avoided. The shovels C are bolted to the bars or beams 134 and extend into close proximity to the bottom of the chamber. The point 139 is in advance of the shank, and from the middle line running backward and upward from said point the surface slopes away, as shown at 140, on both sides for about half the height of the shovel. For the remaining distance the surface on both sides of the middle line slopes toward the center of the chamber, as shown at 141. (See Figs. IV and V.) The effect is that as the shovel plows its way through the material drying or roasting the inclines 140 lift the same from the bottom of the chamberand turn it off to both sides, while the inclines 141 carry it toward the center. The shovels of course also carry the material around with them. Behind each shovel, in the space between the rings thereof, is a brush D, having a stem 142, guided by crossspieces 143, bolted to the wings of the shovel and resting by gravity upon the bottom of the roasting or drying chamber.v These brushes or Scrapers keep the bottom clean and prevent a crust forming. At the center of the chambers the dried or roasted material escapes through outlet-holes in the tube 135.- These outlets are made a distance above the bottom of the chamber, so that a layer of ma- IOO terial of considerable depth is kept always in the cham-ber.' f'

In the ammonia-soda manufacture the moist bicarbonate of sodium is introduced through the hopper 144 into the upper or d rying` chamber, which is heated to a suitable temperature by the combustion in the lire-places beneath it. The bicarbonate is decomposed into a sesqui-carbonate and then in large part into the monohydrated carbonate. The steam,to gether with the ammoniacal vapors and carbonic acid, collects in the dome 145 and is carried off by a pipe leading` from the top of the same. The comparatively-dry soda is de# livered into the Screw conveyer E, which delivers it into the roasting-chamber at the circumference thereof. In this chamber the temperatureis so high that the decomposition is completed, Jthelast equivalent of water of crystallization and' anyremaining carbonio acid beingdriven ott. The gas and vapor pass thrughj theconveyer E'into the dryingchamberfA and escape by way of the dome H555 The roasted soda-(now sodium monocarbonate)y is carried by the conveyer F to thef'eutside of t'lle'apparat'us and delivered intoy anysuitable' receptacle. The -manner of usingftheapparatus with other material will be obvious- It is evidentlthat'modifications could be made'in A'details without 'departing from the' spirit of the-inventiomandparts of the" i-nv vention-"cou'ld be used separately-- Itis not of course essential that there should betwofchain'beis,fsince one ycould be used aloned'or dryingor for roasting, or for both dryingandroasting; A

Havingwnow explained-'the nature of the invention Iand the manner in which'the same ma'yib'efcarried into effect, what -I claim, andA above that portion of l the bottomvof thefsaid" chamber which underlies said inlet, 'in com- -bination with the horizontally-rotating'rakes ing' shovels Whose lower parts arranged below t backward on both sides of their middle-line,

andwhose upper partsV arranged'above said 'outlet areincl'inedto one side, substantially -as described.

said outlet project forward-and are sloped 3. The horizontalv drying or roasting chamf lber provided at the center with a cylindrical tube having outlet-openings therein a-t acon-l siderable distance above the bottom' ofthe said chambeiyin combination with rollers andbrackets supported- 0n-said tube, a stir'rer-A rv`vframe provided with an `inner ring'surrounding saidf tube andrunningon said rollers, vthe-y` shovels attached rto said frame, and the-fgear' fing for rotatingthe 4vsame,l substantially as de-"f` scribed.r y

4. The combination, with the horizontal roasting-or drying chambenfof the horizonsupported each between the Wings of Vonelotf said shovels and movable with the sameand` t pressing against the botto-n1 of said chamber,- l

substantially as described.`

In testimony whereof Iafiixmy'signaturefin f presence ot' two' Witn'essesf HERMAN- FRASCl-I. lVitnesses:

G. W.v HAMMER, DON W: I -IARROM-A .Y 

